RNA-seq of Aspergillus sydowii growing in three different salinity conditions

The mechanisms of cellular and molecular adaptation of fungi to salinity have been commonly drawn from halotolerant strains, although some exceptions in basidiomycete fungi can be found. These studies have been conducted in settings where cells are subjected to stress, either hypo or hyperosmotic, which can be a confounding factor in describing physiological mechanisms related to salinity. Here, we have studied transcriptomic changes in Aspergillus sydowii, a halophilic species, when growing in three different salinity conditions (No salt, 0.5M and 2.0M NaCl). In this fungus salinity related responses occur under high salinity (2.0M NaCl) and not when cultured under optimal conditions (0.5M NaCl), suggesting that in this species, most of the mechanisms described for halophilic growth are a consequence of saline stress response and not an adaptation to saline conditions. A. sydowii grown on wheat straw without NaCl or with 0.5M NaCl and 2.0M NaCl

目前学界对真菌适应盐度的细胞与分子机制的研究，大多源自耐盐菌株，尽管在担子菌（basidiomycete）中存在例外情况。此类研究的实验设置均为细胞处于低渗或高渗胁迫环境，这一条件可能成为阐释盐度相关生理机制的混杂因素。本研究以嗜盐物种 Sydow 曲霉（Aspergillus sydowii）为实验材料，分析其在三种不同盐度条件（无盐、0.5M 及 2.0M 氯化钠（NaCl））下生长时的转录组变化。该真菌的盐度相关响应仅在高盐环境（2.0M NaCl）下被检测到，而在最适培养盐度条件（0.5M NaCl）下则无此类响应，这提示该物种中与嗜盐生长相关的多数机制，实为盐胁迫应答的结果，而非对盐生环境的主动适应。本研究同时涵盖了在无氯化钠、0.5M及2.0M氯化钠的小麦秸秆基质上生长的Sydow曲霉样本。